I just got around to posting this now. Last year, I went out to get a new one gallon gas can to use with my new 2-cycle leaf blower. I was in for quite a surprise when I took it apart to screw the nozzle onto the container. What the heck was this cheapo piece of plastic? And this locking collar? And how do you get the gas out? The sticker on the front of the can gave most of the answers. Twist to "unlock", then push on the nozzle to pour, ideally against the edge of the fill hole on the receiving gas tank. Except, there's more than a few problems with this:
1. At first, gas leaked from the base of the screw-on collar. OK, I tightened that up even more and it stopped.
2. Then, I couldn't get the locking collar into the "unlock" position. After some use of force, it "popped" into position.
3. Every time I tried to fill up my leaf blower, the container leaked just below the unlock collar. Yes, as gas goes into the tank, so does it also go all over the floor. What the hell? These features ... are in the name of safety? But GAS GOES ALL OVER THE FLOOR?
4. Oh, and, as soon as pressure is released from the nozzle, the collar goes back to "lock." Whether you are done or not. What a pain in the a**.
The experience was supremely frustrating. I figured I'd muscle through it, using a towel around the locking collar to fill up and catch the spills, until the container was empty. And maybe return it. But that's no use, because it's not like I was going to get a different spigot. As I found out, some stupid regulations that started in Calfornia several years back were adopted by the EPA and rolled out nationwide. This resulted in the following asinine design changes:
1. Plastic gas cans have no vent anymore. Any idiot knows you use a vent hole in a can when you want to pour liquid, to let air in. Gas cans prior to 2009 all had this. Now they don't. This means the plastic cans can also expand like a balloon in hot weather. This can cause a rush of gas vapor out the spout when you go to use it, or liquid gas to come bubbling out. In some cases the vapor rush has caused explosions (!).
2. The spouts have to lock somehow when not in use, so kids can't pour gas out. The only problem is, the use of locking and unlocking features makes it much harder to legitimately get gas out of the container, resulting in spills all over. Great idea. How about protecting kids by good parenting, showing them what a gas can is and not to touch it, then storing it where they can't reach it? No, let's regulate the crap out of gas can design to make it almost useless instead; and worse, MORE prone to spilling gas all over (like onto hot lawnmowers). You're telling me THAT is not a hazard to the operator?
3. Must save the planet. Yes, all these little gas can vent holes allowed some amount of gas vapor to leak out. And that's contributing to greenhouse gas emissions. Methane from cows farting is probably worse.
Since I wrote this, there are newer variations of the annoying nozzle design, and some are better than others. Shop around and see which cans work better for you. The other option for "for pre-2009 cans only" is an EZ-Pour replacement spout with a vent. Comes in a kit. They're available online. Thanks for nothing, government regulations!